v0.5.19 release (latest)

v0.5.19 release notes for the GitHub Release v0.5.19 (release task: Issue #1058).

Tag state (verified against origin)

Ref	Object	Points at
`v0.5.19`	annotated tag `49bd038c3cbb5b5dcc7c50da7018fdccc04b64d1`	commit `9c6a4510d3efc5345d53dcf270673f244eb4656a`

Docker docs: the ORBI_PI_* table row says PI_API_KEY is written on first start; the entrypoint regenerates the env file on every start (Issue #1052; PR #1057)
Docker Hub overview: README.dockerhub.md docker run block lacks the ORBI_PI_* variables and points at GHCR; runner starts with no model (Issue #1054; PR #1056)